Abstract Protein-based therapeutic products have contributed immensely to healthcare and constitute a large and growing percentage of the total pharmaceutical drugs. The majority of the biopharmaceutical products are currently manufactured using mammalian cell lines, in particular the Chinese hamster ovary (CHO) cell line which accounts for the production of more than 70% of all US licensed therapeutic proteins. Currently, most cell and process development strategies for protein production are performed using a trial and error approach where process outputs are improved laboriously by experimentation. These empirical optimization techniques are widely used because in most cases little is known about the underlying biological factors that impact growth and protein production in the host cell lines. A fundamental understanding of cell line physiology and metabolism can greatly accelerate and improve the process of product development and manufacturing. In response to commercial demands for developing a CHO cell model and building upon our experience with metabolic modeling in microbes and mammalian cells, we have initiated a program to develop an integrated computational and experimental platform for rational design and optimization of protein production in CHO cell lines. This integrated platform combines our advanced modeling technologies with established experimental techniques to accelerate the timelines and to improve the process of therapeutic protein production in the CHO expression system. To demonstrate the advantage of utilizing an integrated computational/experimental approach in this study, we intend to characterize the effect of sodium butyrate supplementation, commonly used to enhance protein expression, on CHO cell metabolism using a metabolic network reconstruction and identify alternative strategies that result in similar improvements in specific productivity without the need to prevent apoptosis (an undesirable side effect of butyrate treatment). Successful completion of the specific aims set forth in this proposal will provide a clear demonstration of the scientific and technical feasibility of developing a rational approach for recombinant protein production in CHO cell lines that can be used to: (a) generate fundamental understanding for cell line response to environmental and genetic changes, and (b) develop novel metabolic interventions for improved protein production. PUBLIC HEALTH RELEVANCE: Protein-based therapeutic products have contributed immensely to health care and constitute a large and growing percentage of t he total pharmaceutical market. The majority of these FDA approved products are currently manufactured using mammalian cell culture systems. However, most cell and process development strategies are performed using a trial and error approach, making biopharmaceutical product development an expensive and lengthy process. The need to optimize the overall process development calls for the use of a rational approach that combines modeling technologies with established experimental techniques to fundamentally change the way host cell lines are developed and therapeutic proteins are produced. Reducing the cost of therapeutic protein development and manufacturing would ensure that the next generation of medicines can be created in amounts large enough to meet patients' needs and at a price low enough that patients can afford them. [unreadable] [unreadable] [unreadable]